added initial support for -exports option, Linux/OpenBSD only for now

bin/mklib

@@ -21,6 +21,7 @@
 #   -arch ARCH    override using `uname` to determine architecture
 #   -archopt OPT  specify an extra achitecture-specific option OPT
 #   -noprefix     don't prefix library name with "lib" or any suffix
+#   -exports FILE only export the symbols listed in FILE
 #
 # The library name should just be "GL" or "GLU", etc.  The 'lib' prefix
 # will be added here if needed, as well as the ".so" or ".a" suffix,
@@ -48,6 +49,7 @@ INSTALLDIR="."
 ARCH="auto"
 ARCHOPT=""
 NOPREFIX=0
+EXPORTS=""
 
 
 #
@@ -68,6 +70,7 @@ do
 	'-arch')      shift 1; ARCH=$1;;
 	'-archopt')   shift 1; ARCHOPT=$1;;
 	'-noprefix')  NOPREFIX=1;;
+	'-exports')   shift 1; EXPORTS=$1;;
 	-*)           echo "mklib: Unknown option: " $1 ; exit 1;;
 	*) break
     esac
@@ -104,6 +107,7 @@ if [  ]  ; then
     echo MINOR is $MINOR
     echo PATCH is $PATCH
     echo DEPS are $DEPS
+    echo "EXPORTS in" $EXPORTS
     echo "-----------------"
 fi
 
@@ -114,7 +118,7 @@ fi
 case $ARCH in
 
     'Linux' | 'OpenBSD')
-	# GCC-based environment
+	# we assume gcc
 
 	# Set default compilers if env vars not set
 	if [ "x$CXX" = "x" ] ; then
@@ -157,6 +161,18 @@ case $ARCH in
 	    else
 		OPTS="-shared -Wl,-soname,${LIBNAME}.so.${MAJOR}"
 	    fi
+	    if [ $EXPORTS ] ; then
+		#OPTS="${OPTS} -Xlinker --retain-symbols-file ${EXPORTS}"
+		# Make the 'exptmp' file for --version-script option
+		echo "VERSION_${MAJOR}.${MINOR} {" > exptmp
+		echo "global:" >> exptmp
+		sed 's/$/;/' ${EXPORTS} >> exptmp
+		echo "local:" >> exptmp
+		echo "*;" >> exptmp
+		echo "};" >> exptmp
+		OPTS="${OPTS} -Xlinker --version-script=exptmp"
+		# exptmp is removed below
+	    fi
 	    if [ x${PATCH} = "x" ] ; then
 		VERSION="${MAJOR}.${MINOR}"
 	    else
@@ -183,6 +199,7 @@ case $ARCH in
             ln -s ${LIBNAME}.so.${MAJOR} ${LIBNAME}.so
             # finish up
             FINAL_LIBS="${LIBNAME}.so.${VERSION} ${LIBNAME}.so.${MAJOR} ${LIBNAME}.so"
+	    rm -f exptmp
         fi
 	;;